Weather Analysis of the Northeast Cold Vortex Rainstorm During July 2-4,2013
Guo Shiyou
Zhong Youjun
Abstract：Based on the NCEP 1° × 1 °reanalysis data and surface precipitation data,the rainstorm occurred in Heilongjiang province on July 2-4,2013 is analyzed.The results are as follows.1) The hour rainfall in Heilongjiang province is mostly less than 10 mm during the influence of northeast cold vortex,but rainfall lasted for a long time,and the cumulative rainfall is more,and the midwest of Heilongjiang province appears rainstorm.2)Strong upward flows and downward flows in the developing stage of northeast cold vortex are the main dynamic factors for rainstorm.3) The low level jet stream from the Yellow Sea and Japan Sea to Heilongjiang province provide sufficient water vapor and energy,and the water vapor flux is higher than 8 g· s-1· cm-1· hPa-1,water vapor convergence is stronger than 2 × 10-5 g·s-1 ·cm-2 ·hPa-1,θse at 850 hPa is higher than 332 K on heavy rainfall area.4)The moist potential vorticity (MPV) change indicate that the upper layer of rainfall area has the convective instability condition,which is advantageous to the heavy rainfall occurrence during the influence of cold vortex.The tongue of positive MPV1 shifted downward vertically and moved eastward at the same time,corresponding to the move of rainstorm area.When the atmospheric inclined pressure is strong in developing stage of northeast cold vortex,rainfall is strong.When atmospheric inclined pressure is weak in maintenance and weakening stage of northeast cold vortex,rainfall is weak.Region MPV2 ＜-0.2 PVU in the lower troposphere often occur rainstorm.
Keywords：northeast cold vortexrainstormmoist potential vorticity
Publication Date：2017-07-02
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 101-109 )